Meds That May Cause Insomnia

How they can cause insomnia: These drugs are thought to work by inhibiting the enzyme in the body that breaks down acetylcholine (a neurotransmitter that's important for alertness, memory, thought and judgment) and thus boosting the amount available to brain cells. This, in theory, slows the patient's loss of memory and helps him or her perform daily activities with fewer problems. But blocking the breakdown of acetylcholine — which is everywhere in the body, not just in the brain — can interfere with all kinds of involuntary body processes and movements, including those related to sleep.

In addition to insomnia and abnormal dreams, the identified side effects of cholinesterase inhibitors include serious changes in heart rhythm, diarrhea, nausea and vomiting as well as leg cramps and muscle spasms — all of which can interfere with normal sleep patterns.

Alternatives: It's important to remember that cholinesterase inhibitors cannot reverse Alzheimer's disease or slow the underlying destruction of nerve cells. And because the Alzheimer's-afflicted brain produces less acetycholine as the disease progresses, all medications in this class eventually lose whatever effectiveness they may be presumed to have.

For these reasons, it may be worthwhile to talk with your doctor (or the doctor treating your loved one) about whether the adverse effects of the drug prescribed outweigh its possible benefits. In my experience, that's nearly always the case.

8. Second-generation (nonsedating) H1 antagonists

Why they're prescribed: H1 antagonists, which are in a class of drugs commonly known as antihistamines, inhibit the body's production of histamine — the chemical that's released when you have an allergic reaction. Elevated histamine levels cause such common allergic reaction symptoms as itching, sneezing, runny nose, watery eyes, nasal congestion and hives.

Second-generation H1 antagonists, also known as nonsedating antihistamines, do not have the same side effects as first-generation antihistamines, such as diphenhydramine (Benadryl), which suppress the central nervous system, causing severe drowsiness.

How they can cause insomnia: In varying degrees, all H1 antagonists block acetylcholine, a nervous system neurotransmitter, and thus can cause anxiety and insomnia.

Alternatives: Since these second-generation antihistamines are typically active in the body for around eight hours, you may find that taking your daily dose in the morning may be all that's needed to resolve any sleep-related problems it may be causing.